Phonograph cabinet



Jan; 12 ,1926. I 1,569,570

J. PETERSON PHONOGRAPH CABINET rif;

Patented Jan. 12, 1926.

UNITED STATES JOHN PETERSON, OF FARIBAULT, MINNESOTA.

PHONOGRAPI-I CABINET.

Application filed. July 22,

To all lwhom t may concern.'

Be it known that l, JoniT Pn'rnnson, a citizen of the United States, resident of Faribault, county of Rice, State of Minneseta, have invented certain new and useful Improvements in lfhonograph Cabinets, of which the following.;` is a specification,

T he object of my invention is to provide a cabinet of such construction that the sound waves will be magnified or intensifiedl to such a degree that spoken words and musical notes will be clear and well defined instead of being mixed and confused, as often is the case with instruments of this kind as ordi narily constructed.

A further and particular object is to provide a phonograph cabinet of a portable type in which the operating mechanism is coinpactly arranged and provision is made for augmenting or magnitying` the sound waves discharged from the cabinet te the end that a comparatively large volume of sound can be obtained by the use of a comparatively small instrument.

Other objects of the invention will appear from the following detailed description.

ln the accompanying drawings forming part of this specification,

Figure 1 is a vertical sectional view through a cabinet embodying my invention,

Figure 2 is a plan view with the cover removed,

Figure 3 is a transverse sectional view,

Figure 4 is a longitudinal sectional view showing a slightly modilied construction,

In the drawing, 2 represents the side walls of the cabinet, having a suitable cover 3 and a top 4 on which the turntable 5 is arranged, driven by the motor G in a chamber 7. The tone arm 8 is mounted in the top 4 and has the usual sound box 9 in which the needle is mounted. From the illustration of my device shown in Figs. 1 or 4 it is apparent that the cover 3 may be closed while the phonograph is being operated and of course such closure would materially dampen or shut off the sounds emitted from the phonograph. By raising the cover and opening the cabinet the sounds emitted from the phonograph could be correspondingly increased. The device may be used in connection with a radio receiver, and in that case, the radio sound box will be placed on the tone arm, in place of the phonograph sound box, and the radio waves intensified by the vaction of the vibrating diaphragm or plate 1922. Serial No. 576,746.

beneath; thus I am able to adapt the device for both phonograph and radio receiver use. Beneath the tone arm is a shallow resonance chamber 10 separated by a partition 11 from the chamber '7 and with this chamber 10 the tone arm conununicates.

rlhe top 4 has an. opening 12 therein coininunicating with the chamber 1() and an e2:-

Atension 13 of the tone arm flared at one end its the underside ot said opening concentric with the base of the tone arm. rlChis ezitension depends to a point preferably about midway of the chamber 10, is spaced from the side walls thereof. Upon each side of the Ysleeve l prefer to provide openings 14 in the top `4 for the passage of the sound waves. ln the bottom of the cabinet l provide a thin floor plate 15, preferably of wood and suliiciently thin to be vibrated by the sound waves when the instrument is in use, the effect of the vibration of `this plato being to magnify or increase the volume of sound and at the same time separate the notes and prevent them from running together or becoming confused, which often occurs-when notes of a high pitch are played or sung. rThis plate may be of any suitable thickness that will insure the proper degree of vibration and as shown in Figure 1, it is preferably located in the bottoni of the cabiw net near the lower end of the extension 125 and fitted into a recess 1G in the lower side walls so that its vibration will not be affected, or interfered with by contact with the table or other support on which the cabinet may be placed.

In Figure 4, I have shown a modi tication which consists in providing a plate 17 of ordinary thickness for the bottom of the cabinet and in the chamber 10 arranging a `thin plate '18 which will vibrate through the action of the sound waves and have substantially the same effect as the plate l5 shown in the other figures.

It will be noted from an examination of the drawings that the iesonance chamber below the tone arm is closed at the bottom and sides and that the flaring lower end of the depending extension of the tone arm is near the surface of the diaphragm or floor of the chamber; said diaphragm being parallel substantially with the top wall of the chamber and the sound waves discharged downwardly through the extension of the tone arm striking it undiminished substantially in volume and setting the diaphragm or loor of the chamber in vibrationand directing such waves increased. in volume baci:- wardly on a line parallel substantially with the axis of the tone arm toward and 'through the discharge openings in the top of the chamber. This manner of handling the sound waves l have found by actual test results in augmenting or. magnitying" the waves to such an extent that the volume thrown out through the discharge openings in the top of the chamber is very materially incrcasel, and l am able to obtainV the desired volume of sound in a cabinet that is small and compact and provided with a comparatively shallow resonance chamber. I havefound that by locating the discharge openings of the sound box or chamber directly opposite the diaphragm that the waves are not interrupted and the sound is not deadened or mullled as it would be where the discharge opening is in the side wall of the: boi; or cabinet in a plane. in angular relation to the' vibrating diaphragm or floor instead o1` parallel therewith.'

I .claim as my invention:

l. An apparatus of the class described comprising ay casing having a compartment therein provided with a comparatively thin flat Hoor plate supported only at its edges and side walls forming a` resonance chamber, a top for said chamber having au opening therein and a tone arm fittingV over saidV opening, an extension of said tone arinf devpending belov7 said top and opening: to a point near said plate, said top also having. a :zound wave discharge opening, the sound waves from said tone arm being directed downwardly by said extension and'striking said plate undiminished substantially in volume and at right angles to said plate-to cause it to vibrate and increase the volume of such waves and direct them backwardly through said wave discharge opening.`

2. An apparatus of the class described comprising a casing having a compartment; therein provided with a comparatively thin iiat vibiatable floor plate and closed side walls at right angles substantially to said floor plate and forming therewith a resonance chamber, a top tor said chamber parallel substantially with said licor; plate: and

having' aii-openingtherein and a tone arm fittingv over said opening, an extension ot' said-tone arm registering with said opening and depending from said top to a pointnear saiditloor plate, said top also having Wave discharge openings upon opposite sides of said extension, the sound waves from said tone arm being directed downwardly by said extension against said plate undiminished substantially in volumeand causing it to vibrate and increase the volume of such waves and pro] ect them backwardly through the openings 1n said top.

3. A; talking machine comprisinga cabi-v net having a compartment therein, suf'- ciently enclosed to form a vibrating body of air whenthe machine is operated, said-compartment being provided with a compara'- tively thin plate forming a sounding board, and walls forming a` resonance chamber, a

wall of saidy chamber having an opening comprising a cabinet having a compartment therein provided with a comparatively thin plate, a top plate extending over said compartment and sides forming a resonance chamber, the top plateofsaid'chamber having an opening therein, and tone arm ending in said opening, an extension of said tone arm extending beyond said opening to a point near said thin plate, said top plate also havingV asound wave discharge opening'7 the sound waves from said tone arm being directed'by saidlextension toward and' against said thin plate causing it to vibrate and increase the volume of such waves and, direct them backwardly through said waive` discharge opening.

InA witness whereof, Il` have" hereunto set my hand this lthdayof July, 1922.

JOHN PETERSON. 

